// Copyright 2011 Baptiste Lepilleur and The JsonCpp Authors
// Distributed under MIT license, or public domain if desired and
// recognized in your jurisdiction.
// See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE

#if !defined(JSON_IS_AMALGAMATION)
#include <assertions.h>
#include <value.h>
#include <writer.h>
#endif // if !defined(JSON_IS_AMALGAMATION)
#include <algorithm>
#include <cassert>
#include <cmath>
#include <cstddef>
#include <cstring>
#include <iostream>
#include <sstream>
#include <utility>

// Provide implementation equivalent of std::snprintf for older _MSC compilers
#if defined(_MSC_VER) && _MSC_VER < 1900
#include <stdarg.h>
static int msvc_pre1900_c99_vsnprintf(char* outBuf, size_t size,
    const char* format, va_list ap)
{
    int count = -1;
    if (size != 0)
        count = _vsnprintf_s(outBuf, size, _TRUNCATE, format, ap);
    if (count == -1)
        count = _vscprintf(format, ap);
    return count;
}

int JSON_API msvc_pre1900_c99_snprintf(char* outBuf, size_t size,
    const char* format, ...)
{
    va_list ap;
    va_start(ap, format);
    const int count = msvc_pre1900_c99_vsnprintf(outBuf, size, format, ap);
    va_end(ap);
    return count;
}
#endif

// Disable warning C4702 : unreachable code
#if defined(_MSC_VER)
#pragma warning(disable : 4702)
#endif

#define JSON_ASSERT_UNREACHABLE assert(false)

namespace Json {
template <typename T>
static std::unique_ptr<T> cloneUnique(const std::unique_ptr<T>& p)
{
    std::unique_ptr<T> r;
    if (p) {
        r = std::unique_ptr<T>(new T(*p));
    }
    return r;
}

// This is a walkaround to avoid the static initialization of Value::null.
// kNull must be word-aligned to avoid crashing on ARM.  We use an alignment of
// 8 (instead of 4) as a bit of future-proofing.
#if defined(__ARMEL__)
#define ALIGNAS(byte_alignment) __attribute__((aligned(byte_alignment)))
#else
#define ALIGNAS(byte_alignment)
#endif

// static
Value const& Value::nullSingleton()
{
    static Value const nullStatic;
    return nullStatic;
}

#if JSON_USE_NULLREF
// for backwards compatibility, we'll leave these global references around, but
// DO NOT use them in JSONCPP library code any more!
// static
Value const& Value::null = Value::nullSingleton();

// static
Value const& Value::nullRef = Value::nullSingleton();
#endif

#if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
template <typename T, typename U>
static inline bool InRange(double d, T min, U max)
{
    // The casts can lose precision, but we are looking only for
    // an approximate range. Might fail on edge cases though. ~cdunn
    return d >= static_cast<double>(min) && d <= static_cast<double>(max);
}
#else // if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
static inline double integerToDouble(Json::UInt64 value)
{
    return static_cast<double>(Int64(value / 2)) * 2.0 + static_cast<double>(Int64(value & 1));
}

template <typename T>
static inline double integerToDouble(T value)
{
    return static_cast<double>(value);
}

template <typename T, typename U>
static inline bool InRange(double d, T min, U max)
{
    return d >= integerToDouble(min) && d <= integerToDouble(max);
}
#endif // if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)

/** Duplicates the specified string value.
 * @param value Pointer to the string to duplicate. Must be zero-terminated if
 *              length is "unknown".
 * @param length Length of the value. if equals to unknown, then it will be
 *               computed using strlen(value).
 * @return Pointer on the duplicate instance of string.
 */
static inline char* duplicateStringValue(const char* value, size_t length)
{
    // Avoid an integer overflow in the call to malloc below by limiting length
    // to a sane value.
    if (length >= static_cast<size_t>(Value::maxInt))
        length = Value::maxInt - 1;

    auto newString = static_cast<char*>(malloc(length + 1));
    if (newString == nullptr) {
        throwRuntimeError("in Json::Value::duplicateStringValue(): "
                          "Failed to allocate string value buffer");
    }
    memcpy(newString, value, length);
    newString[length] = 0;
    return newString;
}

/* Record the length as a prefix.
 */
static inline char* duplicateAndPrefixStringValue(const char* value,
    unsigned int length)
{
    // Avoid an integer overflow in the call to malloc below by limiting length
    // to a sane value.
    JSON_ASSERT_MESSAGE(length <= static_cast<unsigned>(Value::maxInt) - sizeof(unsigned) - 1U,
        "in Json::Value::duplicateAndPrefixStringValue(): "
        "length too big for prefixing");
    size_t actualLength = sizeof(length) + length + 1;
    auto newString = static_cast<char*>(malloc(actualLength));
    if (newString == nullptr) {
        throwRuntimeError("in Json::Value::duplicateAndPrefixStringValue(): "
                          "Failed to allocate string value buffer");
    }
    *reinterpret_cast<unsigned*>(newString) = length;
    memcpy(newString + sizeof(unsigned), value, length);
    newString[actualLength - 1U] = 0; // to avoid buffer over-run accidents by users later
    return newString;
}
inline static void decodePrefixedString(bool isPrefixed, char const* prefixed,
    unsigned* length, char const** value)
{
    if (!isPrefixed) {
        *length = static_cast<unsigned>(strlen(prefixed));
        *value = prefixed;
    } else {
        *length = *reinterpret_cast<unsigned const*>(prefixed);
        *value = prefixed + sizeof(unsigned);
    }
}
/** Free the string duplicated by
 * duplicateStringValue()/duplicateAndPrefixStringValue().
 */
#if JSONCPP_USING_SECURE_MEMORY
static inline void releasePrefixedStringValue(char* value)
{
    unsigned length = 0;
    char const* valueDecoded;
    decodePrefixedString(true, value, &length, &valueDecoded);
    size_t const size = sizeof(unsigned) + length + 1U;
    memset(value, 0, size);
    free(value);
}
static inline void releaseStringValue(char* value, unsigned length)
{
    // length==0 => we allocated the strings memory
    size_t size = (length == 0) ? strlen(value) : length;
    memset(value, 0, size);
    free(value);
}
#else // !JSONCPP_USING_SECURE_MEMORY
static inline void releasePrefixedStringValue(char* value) { free(value); }
static inline void releaseStringValue(char* value, unsigned) { free(value); }
#endif // JSONCPP_USING_SECURE_MEMORY

} // namespace Json

// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// ValueInternals...
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
#if !defined(JSON_IS_AMALGAMATION)

#include "json_valueiterator.inl"
#endif // if !defined(JSON_IS_AMALGAMATION)

namespace Json {

#if JSON_USE_EXCEPTION
Exception::Exception(String msg)
    : msg_(std::move(msg))
{
}
Exception::~Exception() noexcept = default;
char const* Exception::what() const noexcept { return msg_.c_str(); }
RuntimeError::RuntimeError(String const& msg)
    : Exception(msg)
{
}
LogicError::LogicError(String const& msg)
    : Exception(msg)
{
}
JSONCPP_NORETURN void throwRuntimeError(String const& msg)
{
    throw RuntimeError(msg);
}
JSONCPP_NORETURN void throwLogicError(String const& msg)
{
    throw LogicError(msg);
}
#else // !JSON_USE_EXCEPTION
JSONCPP_NORETURN void throwRuntimeError(String const& msg)
{
    std::cerr << msg << std::endl;
    abort();
}
JSONCPP_NORETURN void throwLogicError(String const& msg)
{
    std::cerr << msg << std::endl;
    abort();
}
#endif

// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// class Value::CZString
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////

// Notes: policy_ indicates if the string was allocated when
// a string is stored.

Value::CZString::CZString(ArrayIndex index)
    : cstr_(nullptr)
    , index_(index)
{
}

Value::CZString::CZString(char const* str, unsigned length,
    DuplicationPolicy allocate)
    : cstr_(str)
{
    // allocate != duplicate
    storage_.policy_ = allocate & 0x3;
    storage_.length_ = length & 0x3FFFFFFF;
}

Value::CZString::CZString(const CZString& other)
{
    cstr_ = (other.storage_.policy_ != noDuplication && other.cstr_ != nullptr
            ? duplicateStringValue(other.cstr_, other.storage_.length_)
            : other.cstr_);
    storage_.policy_ = static_cast<unsigned>(
                           other.cstr_
                               ? (static_cast<DuplicationPolicy>(other.storage_.policy_) == noDuplication
                                         ? noDuplication
                                         : duplicate)
                               : static_cast<DuplicationPolicy>(other.storage_.policy_))
        & 3U;
    storage_.length_ = other.storage_.length_;
}

Value::CZString::CZString(CZString&& other) noexcept
    : cstr_(other.cstr_)
    , index_(other.index_)
{
    other.cstr_ = nullptr;
}

Value::CZString::~CZString()
{
    if (cstr_ && storage_.policy_ == duplicate) {
        releaseStringValue(const_cast<char*>(cstr_),
            storage_.length_ + 1U); // +1 for null terminating
                                    // character for sake of
                                    // completeness but not actually
                                    // necessary
    }
}

void Value::CZString::swap(CZString& other)
{
    std::swap(cstr_, other.cstr_);
    std::swap(index_, other.index_);
}

Value::CZString& Value::CZString::operator=(const CZString& other)
{
    cstr_ = other.cstr_;
    index_ = other.index_;
    return *this;
}

Value::CZString& Value::CZString::operator=(CZString&& other) noexcept
{
    cstr_ = other.cstr_;
    index_ = other.index_;
    other.cstr_ = nullptr;
    return *this;
}

bool Value::CZString::operator<(const CZString& other) const
{
    if (!cstr_)
        return index_ < other.index_;
    // return strcmp(cstr_, other.cstr_) < 0;
    // Assume both are strings.
    unsigned this_len = this->storage_.length_;
    unsigned other_len = other.storage_.length_;
    unsigned min_len = std::min<unsigned>(this_len, other_len);
    JSON_ASSERT(this->cstr_ && other.cstr_);
    int comp = memcmp(this->cstr_, other.cstr_, min_len);
    if (comp < 0)
        return true;
    if (comp > 0)
        return false;
    return (this_len < other_len);
}

bool Value::CZString::operator==(const CZString& other) const
{
    if (!cstr_)
        return index_ == other.index_;
    // return strcmp(cstr_, other.cstr_) == 0;
    // Assume both are strings.
    unsigned this_len = this->storage_.length_;
    unsigned other_len = other.storage_.length_;
    if (this_len != other_len)
        return false;
    JSON_ASSERT(this->cstr_ && other.cstr_);
    int comp = memcmp(this->cstr_, other.cstr_, this_len);
    return comp == 0;
}

ArrayIndex Value::CZString::index() const { return index_; }

// const char* Value::CZString::c_str() const { return cstr_; }
const char* Value::CZString::data() const { return cstr_; }
unsigned Value::CZString::length() const { return storage_.length_; }
bool Value::CZString::isStaticString() const
{
    return storage_.policy_ == noDuplication;
}

// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// class Value::Value
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////

/*! \internal Default constructor initialization must be equivalent to:
 * memset( this, 0, sizeof(Value) )
 * This optimization is used in ValueInternalMap fast allocator.
 */
Value::Value(ValueType type)
{
    static char const emptyString[] = "";
    initBasic(type);
    switch (type) {
    case nullValue:
        break;
    case intValue:
    case uintValue:
        value_.int_ = 0;
        break;
    case realValue:
        value_.real_ = 0.0;
        break;
    case stringValue:
        // allocated_ == false, so this is safe.
        value_.string_ = const_cast<char*>(static_cast<char const*>(emptyString));
        break;
    case arrayValue:
    case objectValue:
        value_.map_ = new ObjectValues();
        break;
    case booleanValue:
        value_.bool_ = false;
        break;
    default:
        JSON_ASSERT_UNREACHABLE;
    }
}

Value::Value(Int value)
{
    initBasic(intValue);
    value_.int_ = value;
}

Value::Value(UInt value)
{
    initBasic(uintValue);
    value_.uint_ = value;
}
#if defined(JSON_HAS_INT64)
Value::Value(Int64 value)
{
    initBasic(intValue);
    value_.int_ = value;
}
Value::Value(UInt64 value)
{
    initBasic(uintValue);
    value_.uint_ = value;
}
#endif // defined(JSON_HAS_INT64)

Value::Value(double value)
{
    initBasic(realValue);
    value_.real_ = value;
}

Value::Value(const char* value)
{
    initBasic(stringValue, true);
    JSON_ASSERT_MESSAGE(value != nullptr,
        "Null Value Passed to Value Constructor");
    value_.string_ = duplicateAndPrefixStringValue(
        value, static_cast<unsigned>(strlen(value)));
}

Value::Value(const char* begin, const char* end)
{
    initBasic(stringValue, true);
    value_.string_ = duplicateAndPrefixStringValue(begin, static_cast<unsigned>(end - begin));
}

Value::Value(const String& value)
{
    initBasic(stringValue, true);
    value_.string_ = duplicateAndPrefixStringValue(
        value.data(), static_cast<unsigned>(value.length()));
}

Value::Value(const StaticString& value)
{
    initBasic(stringValue);
    value_.string_ = const_cast<char*>(value.c_str());
}

Value::Value(bool value)
{
    initBasic(booleanValue);
    value_.bool_ = value;
}

Value::Value(const Value& other)
{
    dupPayload(other);
    dupMeta(other);
}

Value::Value(Value&& other) noexcept
{
    initBasic(nullValue);
    swap(other);
}

Value::~Value()
{
    releasePayload();
    value_.uint_ = 0;
}

Value& Value::operator=(const Value& other)
{
    Value(other).swap(*this);
    return *this;
}

Value& Value::operator=(Value&& other) noexcept
{
    other.swap(*this);
    return *this;
}

void Value::swapPayload(Value& other)
{
    std::swap(bits_, other.bits_);
    std::swap(value_, other.value_);
}

void Value::copyPayload(const Value& other)
{
    releasePayload();
    dupPayload(other);
}

void Value::swap(Value& other)
{
    swapPayload(other);
    std::swap(comments_, other.comments_);
    std::swap(start_, other.start_);
    std::swap(limit_, other.limit_);
}

void Value::copy(const Value& other)
{
    copyPayload(other);
    dupMeta(other);
}

ValueType Value::type() const
{
    return static_cast<ValueType>(bits_.value_type_);
}

int Value::compare(const Value& other) const
{
    if (*this < other)
        return -1;
    if (*this > other)
        return 1;
    return 0;
}

bool Value::operator<(const Value& other) const
{
    int typeDelta = type() - other.type();
    if (typeDelta)
        return typeDelta < 0;
    switch (type()) {
    case nullValue:
        return false;
    case intValue:
        return value_.int_ < other.value_.int_;
    case uintValue:
        return value_.uint_ < other.value_.uint_;
    case realValue:
        return value_.real_ < other.value_.real_;
    case booleanValue:
        return value_.bool_ < other.value_.bool_;
    case stringValue: {
        if ((value_.string_ == nullptr) || (other.value_.string_ == nullptr)) {
            return other.value_.string_ != nullptr;
        }
        unsigned this_len;
        unsigned other_len;
        char const* this_str;
        char const* other_str;
        decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
            &this_str);
        decodePrefixedString(other.isAllocated(), other.value_.string_, &other_len,
            &other_str);
        unsigned min_len = std::min<unsigned>(this_len, other_len);
        JSON_ASSERT(this_str && other_str);
        int comp = memcmp(this_str, other_str, min_len);
        if (comp < 0)
            return true;
        if (comp > 0)
            return false;
        return (this_len < other_len);
    }
    case arrayValue:
    case objectValue: {
        auto thisSize = value_.map_->size();
        auto otherSize = other.value_.map_->size();
        if (thisSize != otherSize)
            return thisSize < otherSize;
        return (*value_.map_) < (*other.value_.map_);
    }
    default:
        JSON_ASSERT_UNREACHABLE;
    }
    return false; // unreachable
}

bool Value::operator<=(const Value& other) const { return !(other < *this); }

bool Value::operator>=(const Value& other) const { return !(*this < other); }

bool Value::operator>(const Value& other) const { return other < *this; }

bool Value::operator==(const Value& other) const
{
    if (type() != other.type())
        return false;
    switch (type()) {
    case nullValue:
        return true;
    case intValue:
        return value_.int_ == other.value_.int_;
    case uintValue:
        return value_.uint_ == other.value_.uint_;
    case realValue:
        return value_.real_ == other.value_.real_;
    case booleanValue:
        return value_.bool_ == other.value_.bool_;
    case stringValue: {
        if ((value_.string_ == nullptr) || (other.value_.string_ == nullptr)) {
            return (value_.string_ == other.value_.string_);
        }
        unsigned this_len;
        unsigned other_len;
        char const* this_str;
        char const* other_str;
        decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
            &this_str);
        decodePrefixedString(other.isAllocated(), other.value_.string_, &other_len,
            &other_str);
        if (this_len != other_len)
            return false;
        JSON_ASSERT(this_str && other_str);
        int comp = memcmp(this_str, other_str, this_len);
        return comp == 0;
    }
    case arrayValue:
    case objectValue:
        return value_.map_->size() == other.value_.map_->size() && (*value_.map_) == (*other.value_.map_);
    default:
        JSON_ASSERT_UNREACHABLE;
    }
    return false; // unreachable
}

bool Value::operator!=(const Value& other) const { return !(*this == other); }

const char* Value::asCString() const
{
    JSON_ASSERT_MESSAGE(type() == stringValue,
        "in Json::Value::asCString(): requires stringValue");
    if (value_.string_ == nullptr)
        return nullptr;
    unsigned this_len;
    char const* this_str;
    decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
        &this_str);
    return this_str;
}

#if JSONCPP_USING_SECURE_MEMORY
unsigned Value::getCStringLength() const
{
    JSON_ASSERT_MESSAGE(type() == stringValue,
        "in Json::Value::asCString(): requires stringValue");
    if (value_.string_ == 0)
        return 0;
    unsigned this_len;
    char const* this_str;
    decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
        &this_str);
    return this_len;
}
#endif

bool Value::getString(char const** begin, char const** end) const
{
    if (type() != stringValue)
        return false;
    if (value_.string_ == nullptr)
        return false;
    unsigned length;
    decodePrefixedString(this->isAllocated(), this->value_.string_, &length,
        begin);
    *end = *begin + length;
    return true;
}

String Value::asString() const
{
    switch (type()) {
    case nullValue:
        return "";
    case stringValue: {
        if (value_.string_ == nullptr)
            return "";
        unsigned this_len;
        char const* this_str;
        decodePrefixedString(this->isAllocated(), this->value_.string_, &this_len,
            &this_str);
        return String(this_str, this_len);
    }
    case booleanValue:
        return value_.bool_ ? "true" : "false";
    case intValue:
        return valueToString(value_.int_);
    case uintValue:
        return valueToString(value_.uint_);
    case realValue:
        return valueToString(value_.real_);
    default:
        JSON_FAIL_MESSAGE("Type is not convertible to string");
    }
}

Value::Int Value::asInt() const
{
    switch (type()) {
    case intValue:
        JSON_ASSERT_MESSAGE(isInt(), "LargestInt out of Int range");
        return Int(value_.int_);
    case uintValue:
        JSON_ASSERT_MESSAGE(isInt(), "LargestUInt out of Int range");
        return Int(value_.uint_);
    case realValue:
        JSON_ASSERT_MESSAGE(InRange(value_.real_, minInt, maxInt),
            "double out of Int range");
        return Int(value_.real_);
    case nullValue:
        return 0;
    case booleanValue:
        return value_.bool_ ? 1 : 0;
    default:
        break;
    }
    JSON_FAIL_MESSAGE("Value is not convertible to Int.");
}

Value::UInt Value::asUInt() const
{
    switch (type()) {
    case intValue:
        JSON_ASSERT_MESSAGE(isUInt(), "LargestInt out of UInt range");
        return UInt(value_.int_);
    case uintValue:
        JSON_ASSERT_MESSAGE(isUInt(), "LargestUInt out of UInt range");
        return UInt(value_.uint_);
    case realValue:
        JSON_ASSERT_MESSAGE(InRange(value_.real_, 0, maxUInt),
            "double out of UInt range");
        return UInt(value_.real_);
    case nullValue:
        return 0;
    case booleanValue:
        return value_.bool_ ? 1 : 0;
    default:
        break;
    }
    JSON_FAIL_MESSAGE("Value is not convertible to UInt.");
}

#if defined(JSON_HAS_INT64)

Value::Int64 Value::asInt64() const
{
    switch (type()) {
    case intValue:
        return Int64(value_.int_);
    case uintValue:
        JSON_ASSERT_MESSAGE(isInt64(), "LargestUInt out of Int64 range");
        return Int64(value_.uint_);
    case realValue:
        JSON_ASSERT_MESSAGE(InRange(value_.real_, minInt64, maxInt64),
            "double out of Int64 range");
        return Int64(value_.real_);
    case nullValue:
        return 0;
    case booleanValue:
        return value_.bool_ ? 1 : 0;
    default:
        break;
    }
    JSON_FAIL_MESSAGE("Value is not convertible to Int64.");
}

Value::UInt64 Value::asUInt64() const
{
    switch (type()) {
    case intValue:
        JSON_ASSERT_MESSAGE(isUInt64(), "LargestInt out of UInt64 range");
        return UInt64(value_.int_);
    case uintValue:
        return UInt64(value_.uint_);
    case realValue:
        JSON_ASSERT_MESSAGE(InRange(value_.real_, 0, maxUInt64),
            "double out of UInt64 range");
        return UInt64(value_.real_);
    case nullValue:
        return 0;
    case booleanValue:
        return value_.bool_ ? 1 : 0;
    default:
        break;
    }
    JSON_FAIL_MESSAGE("Value is not convertible to UInt64.");
}
#endif // if defined(JSON_HAS_INT64)

LargestInt Value::asLargestInt() const
{
#if defined(JSON_NO_INT64)
    return asInt();
#else
    return asInt64();
#endif
}

LargestUInt Value::asLargestUInt() const
{
#if defined(JSON_NO_INT64)
    return asUInt();
#else
    return asUInt64();
#endif
}

double Value::asDouble() const
{
    switch (type()) {
    case intValue:
        return static_cast<double>(value_.int_);
    case uintValue:
#if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
        return static_cast<double>(value_.uint_);
#else // if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
        return integerToDouble(value_.uint_);
#endif // if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
    case realValue:
        return value_.real_;
    case nullValue:
        return 0.0;
    case booleanValue:
        return value_.bool_ ? 1.0 : 0.0;
    default:
        break;
    }
    JSON_FAIL_MESSAGE("Value is not convertible to double.");
}

float Value::asFloat() const
{
    switch (type()) {
    case intValue:
        return static_cast<float>(value_.int_);
    case uintValue:
#if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
        return static_cast<float>(value_.uint_);
#else // if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
        // This can fail (silently?) if the value is bigger than MAX_FLOAT.
        return static_cast<float>(integerToDouble(value_.uint_));
#endif // if !defined(JSON_USE_INT64_DOUBLE_CONVERSION)
    case realValue:
        return static_cast<float>(value_.real_);
    case nullValue:
        return 0.0;
    case booleanValue:
        return value_.bool_ ? 1.0F : 0.0F;
    default:
        break;
    }
    JSON_FAIL_MESSAGE("Value is not convertible to float.");
}

bool Value::asBool() const
{
    switch (type()) {
    case booleanValue:
        return value_.bool_;
    case nullValue:
        return false;
    case intValue:
        return value_.int_ != 0;
    case uintValue:
        return value_.uint_ != 0;
    case realValue: {
        // According to JavaScript language zero or NaN is regarded as false
        const auto value_classification = std::fpclassify(value_.real_);
        return value_classification != FP_ZERO && value_classification != FP_NAN;
    }
    default:
        break;
    }
    JSON_FAIL_MESSAGE("Value is not convertible to bool.");
}

bool Value::isConvertibleTo(ValueType other) const
{
    switch (other) {
    case nullValue:
        return (isNumeric() && asDouble() == 0.0) || (type() == booleanValue && !value_.bool_) || (type() == stringValue && asString().empty()) || (type() == arrayValue && value_.map_->empty()) || (type() == objectValue && value_.map_->empty()) || type() == nullValue;
    case intValue:
        return isInt() || (type() == realValue && InRange(value_.real_, minInt, maxInt)) || type() == booleanValue || type() == nullValue;
    case uintValue:
        return isUInt() || (type() == realValue && InRange(value_.real_, 0, maxUInt)) || type() == booleanValue || type() == nullValue;
    case realValue:
        return isNumeric() || type() == booleanValue || type() == nullValue;
    case booleanValue:
        return isNumeric() || type() == booleanValue || type() == nullValue;
    case stringValue:
        return isNumeric() || type() == booleanValue || type() == stringValue || type() == nullValue;
    case arrayValue:
        return type() == arrayValue || type() == nullValue;
    case objectValue:
        return type() == objectValue || type() == nullValue;
    }
    JSON_ASSERT_UNREACHABLE;
    return false;
}

/// Number of values in array or object
ArrayIndex Value::size() const
{
    switch (type()) {
    case nullValue:
    case intValue:
    case uintValue:
    case realValue:
    case booleanValue:
    case stringValue:
        return 0;
    case arrayValue: // size of the array is highest index + 1
        if (!value_.map_->empty()) {
            ObjectValues::const_iterator itLast = value_.map_->end();
            --itLast;
            return (*itLast).first.index() + 1;
        }
        return 0;
    case objectValue:
        return ArrayIndex(value_.map_->size());
    }
    JSON_ASSERT_UNREACHABLE;
    return 0; // unreachable;
}

bool Value::empty() const
{
    if (isNull() || isArray() || isObject())
        return size() == 0U;
    return false;
}

Value::operator bool() const { return !isNull(); }

void Value::clear()
{
    JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue || type() == objectValue,
        "in Json::Value::clear(): requires complex value");
    start_ = 0;
    limit_ = 0;
    switch (type()) {
    case arrayValue:
    case objectValue:
        value_.map_->clear();
        break;
    default:
        break;
    }
}

void Value::resize(ArrayIndex newSize)
{
    JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue,
        "in Json::Value::resize(): requires arrayValue");
    if (type() == nullValue)
        *this = Value(arrayValue);
    ArrayIndex oldSize = size();
    if (newSize == 0)
        clear();
    else if (newSize > oldSize)
        for (ArrayIndex i = oldSize; i < newSize; ++i)
            (*this)[i];
    else {
        for (ArrayIndex index = newSize; index < oldSize; ++index) {
            value_.map_->erase(index);
        }
        JSON_ASSERT(size() == newSize);
    }
}

Value& Value::operator[](ArrayIndex index)
{
    JSON_ASSERT_MESSAGE(
        type() == nullValue || type() == arrayValue,
        "in Json::Value::operator[](ArrayIndex): requires arrayValue");
    if (type() == nullValue)
        *this = Value(arrayValue);
    CZString key(index);
    auto it = value_.map_->lower_bound(key);
    if (it != value_.map_->end() && (*it).first == key)
        return (*it).second;

    ObjectValues::value_type defaultValue(key, nullSingleton());
    it = value_.map_->insert(it, defaultValue);
    return (*it).second;
}

Value& Value::operator[](int index)
{
    JSON_ASSERT_MESSAGE(
        index >= 0,
        "in Json::Value::operator[](int index): index cannot be negative");
    return (*this)[ArrayIndex(index)];
}

const Value& Value::operator[](ArrayIndex index) const
{
    JSON_ASSERT_MESSAGE(
        type() == nullValue || type() == arrayValue,
        "in Json::Value::operator[](ArrayIndex)const: requires arrayValue");
    if (type() == nullValue)
        return nullSingleton();
    CZString key(index);
    ObjectValues::const_iterator it = value_.map_->find(key);
    if (it == value_.map_->end())
        return nullSingleton();
    return (*it).second;
}

const Value& Value::operator[](int index) const
{
    JSON_ASSERT_MESSAGE(
        index >= 0,
        "in Json::Value::operator[](int index) const: index cannot be negative");
    return (*this)[ArrayIndex(index)];
}

void Value::initBasic(ValueType type, bool allocated)
{
    setType(type);
    setIsAllocated(allocated);
    comments_ = Comments {};
    start_ = 0;
    limit_ = 0;
}

void Value::dupPayload(const Value& other)
{
    setType(other.type());
    setIsAllocated(false);
    switch (type()) {
    case nullValue:
    case intValue:
    case uintValue:
    case realValue:
    case booleanValue:
        value_ = other.value_;
        break;
    case stringValue:
        if (other.value_.string_ && other.isAllocated()) {
            unsigned len;
            char const* str;
            decodePrefixedString(other.isAllocated(), other.value_.string_, &len,
                &str);
            value_.string_ = duplicateAndPrefixStringValue(str, len);
            setIsAllocated(true);
        } else {
            value_.string_ = other.value_.string_;
        }
        break;
    case arrayValue:
    case objectValue:
        value_.map_ = new ObjectValues(*other.value_.map_);
        break;
    default:
        JSON_ASSERT_UNREACHABLE;
    }
}

void Value::releasePayload()
{
    switch (type()) {
    case nullValue:
    case intValue:
    case uintValue:
    case realValue:
    case booleanValue:
        break;
    case stringValue:
        if (isAllocated())
            releasePrefixedStringValue(value_.string_);
        break;
    case arrayValue:
    case objectValue:
        delete value_.map_;
        break;
    default:
        JSON_ASSERT_UNREACHABLE;
    }
}

void Value::dupMeta(const Value& other)
{
    comments_ = other.comments_;
    start_ = other.start_;
    limit_ = other.limit_;
}

// Access an object value by name, create a null member if it does not exist.
// @pre Type of '*this' is object or null.
// @param key is null-terminated.
Value& Value::resolveReference(const char* key)
{
    JSON_ASSERT_MESSAGE(
        type() == nullValue || type() == objectValue,
        "in Json::Value::resolveReference(): requires objectValue");
    if (type() == nullValue)
        *this = Value(objectValue);
    CZString actualKey(key, static_cast<unsigned>(strlen(key)),
        CZString::noDuplication); // NOTE!
    auto it = value_.map_->lower_bound(actualKey);
    if (it != value_.map_->end() && (*it).first == actualKey)
        return (*it).second;

    ObjectValues::value_type defaultValue(actualKey, nullSingleton());
    it = value_.map_->insert(it, defaultValue);
    Value& value = (*it).second;
    return value;
}

// @param key is not null-terminated.
Value& Value::resolveReference(char const* key, char const* end)
{
    JSON_ASSERT_MESSAGE(
        type() == nullValue || type() == objectValue,
        "in Json::Value::resolveReference(key, end): requires objectValue");
    if (type() == nullValue)
        *this = Value(objectValue);
    CZString actualKey(key, static_cast<unsigned>(end - key),
        CZString::duplicateOnCopy);
    auto it = value_.map_->lower_bound(actualKey);
    if (it != value_.map_->end() && (*it).first == actualKey)
        return (*it).second;

    ObjectValues::value_type defaultValue(actualKey, nullSingleton());
    it = value_.map_->insert(it, defaultValue);
    Value& value = (*it).second;
    return value;
}

Value Value::get(ArrayIndex index, const Value& defaultValue) const
{
    const Value* value = &((*this)[index]);
    return value == &nullSingleton() ? defaultValue : *value;
}

bool Value::isValidIndex(ArrayIndex index) const { return index < size(); }

Value const* Value::find(char const* begin, char const* end) const
{
    JSON_ASSERT_MESSAGE(type() == nullValue || type() == objectValue,
        "in Json::Value::find(begin, end): requires "
        "objectValue or nullValue");
    if (type() == nullValue)
        return nullptr;
    CZString actualKey(begin, static_cast<unsigned>(end - begin),
        CZString::noDuplication);
    ObjectValues::const_iterator it = value_.map_->find(actualKey);
    if (it == value_.map_->end())
        return nullptr;
    return &(*it).second;
}
Value* Value::demand(char const* begin, char const* end)
{
    JSON_ASSERT_MESSAGE(type() == nullValue || type() == objectValue,
        "in Json::Value::demand(begin, end): requires "
        "objectValue or nullValue");
    return &resolveReference(begin, end);
}
const Value& Value::operator[](const char* key) const
{
    Value const* found = find(key, key + strlen(key));
    if (!found)
        return nullSingleton();
    return *found;
}
Value const& Value::operator[](const String& key) const
{
    Value const* found = find(key.data(), key.data() + key.length());
    if (!found)
        return nullSingleton();
    return *found;
}

Value& Value::operator[](const char* key)
{
    return resolveReference(key, key + strlen(key));
}

Value& Value::operator[](const String& key)
{
    return resolveReference(key.data(), key.data() + key.length());
}

Value& Value::operator[](const StaticString& key)
{
    return resolveReference(key.c_str());
}

Value& Value::append(const Value& value) { return append(Value(value)); }

Value& Value::append(Value&& value)
{
    JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue,
        "in Json::Value::append: requires arrayValue");
    if (type() == nullValue) {
        *this = Value(arrayValue);
    }
    return this->value_.map_->emplace(size(), std::move(value)).first->second;
}

bool Value::insert(ArrayIndex index, const Value& newValue)
{
    return insert(index, Value(newValue));
}

bool Value::insert(ArrayIndex index, Value&& newValue)
{
    JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue,
        "in Json::Value::insert: requires arrayValue");
    ArrayIndex length = size();
    if (index > length) {
        return false;
    }
    for (ArrayIndex i = length; i > index; i--) {
        (*this)[i] = std::move((*this)[i - 1]);
    }
    (*this)[index] = std::move(newValue);
    return true;
}

Value Value::get(char const* begin, char const* end,
    Value const& defaultValue) const
{
    Value const* found = find(begin, end);
    return !found ? defaultValue : *found;
}
Value Value::get(char const* key, Value const& defaultValue) const
{
    return get(key, key + strlen(key), defaultValue);
}
Value Value::get(String const& key, Value const& defaultValue) const
{
    return get(key.data(), key.data() + key.length(), defaultValue);
}

bool Value::removeMember(const char* begin, const char* end, Value* removed)
{
    if (type() != objectValue) {
        return false;
    }
    CZString actualKey(begin, static_cast<unsigned>(end - begin),
        CZString::noDuplication);
    auto it = value_.map_->find(actualKey);
    if (it == value_.map_->end())
        return false;
    if (removed)
        *removed = std::move(it->second);
    value_.map_->erase(it);
    return true;
}
bool Value::removeMember(const char* key, Value* removed)
{
    return removeMember(key, key + strlen(key), removed);
}
bool Value::removeMember(String const& key, Value* removed)
{
    return removeMember(key.data(), key.data() + key.length(), removed);
}
void Value::removeMember(const char* key)
{
    JSON_ASSERT_MESSAGE(type() == nullValue || type() == objectValue,
        "in Json::Value::removeMember(): requires objectValue");
    if (type() == nullValue)
        return;

    CZString actualKey(key, unsigned(strlen(key)), CZString::noDuplication);
    value_.map_->erase(actualKey);
}
void Value::removeMember(const String& key) { removeMember(key.c_str()); }

bool Value::removeIndex(ArrayIndex index, Value* removed)
{
    if (type() != arrayValue) {
        return false;
    }
    CZString key(index);
    auto it = value_.map_->find(key);
    if (it == value_.map_->end()) {
        return false;
    }
    if (removed)
        *removed = it->second;
    ArrayIndex oldSize = size();
    // shift left all items left, into the place of the "removed"
    for (ArrayIndex i = index; i < (oldSize - 1); ++i) {
        CZString keey(i);
        (*value_.map_)[keey] = (*this)[i + 1];
    }
    // erase the last one ("leftover")
    CZString keyLast(oldSize - 1);
    auto itLast = value_.map_->find(keyLast);
    value_.map_->erase(itLast);
    return true;
}

bool Value::isMember(char const* begin, char const* end) const
{
    Value const* value = find(begin, end);
    return nullptr != value;
}
bool Value::isMember(char const* key) const
{
    return isMember(key, key + strlen(key));
}
bool Value::isMember(String const& key) const
{
    return isMember(key.data(), key.data() + key.length());
}

Value::Members Value::getMemberNames() const
{
    JSON_ASSERT_MESSAGE(
        type() == nullValue || type() == objectValue,
        "in Json::Value::getMemberNames(), value must be objectValue");
    if (type() == nullValue)
        return Value::Members();
    Members members;
    members.reserve(value_.map_->size());
    ObjectValues::const_iterator it = value_.map_->begin();
    ObjectValues::const_iterator itEnd = value_.map_->end();
    for (; it != itEnd; ++it) {
        members.push_back(String((*it).first.data(), (*it).first.length()));
    }
    return members;
}

static bool IsIntegral(double d)
{
    double integral_part;
    return modf(d, &integral_part) == 0.0;
}

bool Value::isNull() const { return type() == nullValue; }

bool Value::isBool() const { return type() == booleanValue; }

bool Value::isInt() const
{
    switch (type()) {
    case intValue:
#if defined(JSON_HAS_INT64)
        return value_.int_ >= minInt && value_.int_ <= maxInt;
#else
        return true;
#endif
    case uintValue:
        return value_.uint_ <= UInt(maxInt);
    case realValue:
        return value_.real_ >= minInt && value_.real_ <= maxInt && IsIntegral(value_.real_);
    default:
        break;
    }
    return false;
}

bool Value::isUInt() const
{
    switch (type()) {
    case intValue:
#if defined(JSON_HAS_INT64)
        return value_.int_ >= 0 && LargestUInt(value_.int_) <= LargestUInt(maxUInt);
#else
        return value_.int_ >= 0;
#endif
    case uintValue:
#if defined(JSON_HAS_INT64)
        return value_.uint_ <= maxUInt;
#else
        return true;
#endif
    case realValue:
        return value_.real_ >= 0 && value_.real_ <= maxUInt && IsIntegral(value_.real_);
    default:
        break;
    }
    return false;
}

bool Value::isInt64() const
{
#if defined(JSON_HAS_INT64)
    switch (type()) {
    case intValue:
        return true;
    case uintValue:
        return value_.uint_ <= UInt64(maxInt64);
    case realValue:
        // Note that maxInt64 (= 2^63 - 1) is not exactly representable as a
        // double, so double(maxInt64) will be rounded up to 2^63. Therefore we
        // require the value to be strictly less than the limit.
        return value_.real_ >= double(minInt64) && value_.real_ < double(maxInt64) && IsIntegral(value_.real_);
    default:
        break;
    }
#endif // JSON_HAS_INT64
    return false;
}

bool Value::isUInt64() const
{
#if defined(JSON_HAS_INT64)
    switch (type()) {
    case intValue:
        return value_.int_ >= 0;
    case uintValue:
        return true;
    case realValue:
        // Note that maxUInt64 (= 2^64 - 1) is not exactly representable as a
        // double, so double(maxUInt64) will be rounded up to 2^64. Therefore we
        // require the value to be strictly less than the limit.
        return value_.real_ >= 0 && value_.real_ < maxUInt64AsDouble && IsIntegral(value_.real_);
    default:
        break;
    }
#endif // JSON_HAS_INT64
    return false;
}

bool Value::isIntegral() const
{
    switch (type()) {
    case intValue:
    case uintValue:
        return true;
    case realValue:
#if defined(JSON_HAS_INT64)
        // Note that maxUInt64 (= 2^64 - 1) is not exactly representable as a
        // double, so double(maxUInt64) will be rounded up to 2^64. Therefore we
        // require the value to be strictly less than the limit.
        return value_.real_ >= double(minInt64) && value_.real_ < maxUInt64AsDouble && IsIntegral(value_.real_);
#else
        return value_.real_ >= minInt && value_.real_ <= maxUInt && IsIntegral(value_.real_);
#endif // JSON_HAS_INT64
    default:
        break;
    }
    return false;
}

bool Value::isDouble() const
{
    return type() == intValue || type() == uintValue || type() == realValue;
}

bool Value::isNumeric() const { return isDouble(); }

bool Value::isString() const { return type() == stringValue; }

bool Value::isArray() const { return type() == arrayValue; }

bool Value::isObject() const { return type() == objectValue; }

Value::Comments::Comments(const Comments& that)
    : ptr_ { cloneUnique(that.ptr_) }
{
}

Value::Comments::Comments(Comments&& that) noexcept
    : ptr_ { std::move(that.ptr_) }
{
}

Value::Comments& Value::Comments::operator=(const Comments& that)
{
    ptr_ = cloneUnique(that.ptr_);
    return *this;
}

Value::Comments& Value::Comments::operator=(Comments&& that) noexcept
{
    ptr_ = std::move(that.ptr_);
    return *this;
}

bool Value::Comments::has(CommentPlacement slot) const
{
    return ptr_ && !(*ptr_)[slot].empty();
}

String Value::Comments::get(CommentPlacement slot) const
{
    if (!ptr_)
        return {};
    return (*ptr_)[slot];
}

void Value::Comments::set(CommentPlacement slot, String comment)
{
    if (slot >= CommentPlacement::numberOfCommentPlacement)
        return;
    if (!ptr_)
        ptr_ = std::unique_ptr<Array>(new Array());
    (*ptr_)[slot] = std::move(comment);
}

void Value::setComment(String comment, CommentPlacement placement)
{
    if (!comment.empty() && (comment.back() == '\n')) {
        // Always discard trailing newline, to aid indentation.
        comment.pop_back();
    }
    JSON_ASSERT(!comment.empty());
    JSON_ASSERT_MESSAGE(
        comment[0] == '\0' || comment[0] == '/',
        "in Json::Value::setComment(): Comments must start with /");
    comments_.set(placement, std::move(comment));
}

bool Value::hasComment(CommentPlacement placement) const
{
    return comments_.has(placement);
}

String Value::getComment(CommentPlacement placement) const
{
    return comments_.get(placement);
}

void Value::setOffsetStart(ptrdiff_t start) { start_ = start; }

void Value::setOffsetLimit(ptrdiff_t limit) { limit_ = limit; }

ptrdiff_t Value::getOffsetStart() const { return start_; }

ptrdiff_t Value::getOffsetLimit() const { return limit_; }

String Value::toStyledString() const
{
    StreamWriterBuilder builder;

    String out = this->hasComment(commentBefore) ? "\n" : "";
    out += Json::writeString(builder, *this);
    out += '\n';

    return out;
}

Value::const_iterator Value::begin() const
{
    switch (type()) {
    case arrayValue:
    case objectValue:
        if (value_.map_)
            return const_iterator(value_.map_->begin());
        break;
    default:
        break;
    }
    return {};
}

Value::const_iterator Value::end() const
{
    switch (type()) {
    case arrayValue:
    case objectValue:
        if (value_.map_)
            return const_iterator(value_.map_->end());
        break;
    default:
        break;
    }
    return {};
}

Value::iterator Value::begin()
{
    switch (type()) {
    case arrayValue:
    case objectValue:
        if (value_.map_)
            return iterator(value_.map_->begin());
        break;
    default:
        break;
    }
    return iterator();
}

Value::iterator Value::end()
{
    switch (type()) {
    case arrayValue:
    case objectValue:
        if (value_.map_)
            return iterator(value_.map_->end());
        break;
    default:
        break;
    }
    return iterator();
}

// class PathArgument
// //////////////////////////////////////////////////////////////////

PathArgument::PathArgument() = default;

PathArgument::PathArgument(ArrayIndex index)
    : index_(index)
    , kind_(kindIndex)
{
}

PathArgument::PathArgument(const char* key)
    : key_(key)
    , kind_(kindKey)
{
}

PathArgument::PathArgument(String key)
    : key_(std::move(key))
    , kind_(kindKey)
{
}

// class Path
// //////////////////////////////////////////////////////////////////

Path::Path(const String& path, const PathArgument& a1, const PathArgument& a2,
    const PathArgument& a3, const PathArgument& a4,
    const PathArgument& a5)
{
    InArgs in;
    in.reserve(5);
    in.push_back(&a1);
    in.push_back(&a2);
    in.push_back(&a3);
    in.push_back(&a4);
    in.push_back(&a5);
    makePath(path, in);
}

void Path::makePath(const String& path, const InArgs& in)
{
    const char* current = path.c_str();
    const char* end = current + path.length();
    auto itInArg = in.begin();
    while (current != end) {
        if (*current == '[') {
            ++current;
            if (*current == '%')
                addPathInArg(path, in, itInArg, PathArgument::kindIndex);
            else {
                ArrayIndex index = 0;
                for (; current != end && *current >= '0' && *current <= '9'; ++current)
                    index = index * 10 + ArrayIndex(*current - '0');
                args_.push_back(index);
            }
            if (current == end || *++current != ']')
                invalidPath(path, int(current - path.c_str()));
        } else if (*current == '%') {
            addPathInArg(path, in, itInArg, PathArgument::kindKey);
            ++current;
        } else if (*current == '.' || *current == ']') {
            ++current;
        } else {
            const char* beginName = current;
            while (current != end && !strchr("[.", *current))
                ++current;
            args_.push_back(String(beginName, current));
        }
    }
}

void Path::addPathInArg(const String& /*path*/, const InArgs& in,
    InArgs::const_iterator& itInArg,
    PathArgument::Kind kind)
{
    if (itInArg == in.end()) {
        // Error: missing argument %d
    } else if ((*itInArg)->kind_ != kind) {
        // Error: bad argument type
    } else {
        args_.push_back(**itInArg++);
    }
}

void Path::invalidPath(const String& /*path*/, int /*location*/)
{
    // Error: invalid path.
}

const Value& Path::resolve(const Value& root) const
{
    const Value* node = &root;
    for (const auto& arg : args_) {
        if (arg.kind_ == PathArgument::kindIndex) {
            if (!node->isArray() || !node->isValidIndex(arg.index_)) {
                // Error: unable to resolve path (array value expected at position... )
                return Value::nullSingleton();
            }
            node = &((*node)[arg.index_]);
        } else if (arg.kind_ == PathArgument::kindKey) {
            if (!node->isObject()) {
                // Error: unable to resolve path (object value expected at position...)
                return Value::nullSingleton();
            }
            node = &((*node)[arg.key_]);
            if (node == &Value::nullSingleton()) {
                // Error: unable to resolve path (object has no member named '' at
                // position...)
                return Value::nullSingleton();
            }
        }
    }
    return *node;
}

Value Path::resolve(const Value& root, const Value& defaultValue) const
{
    const Value* node = &root;
    for (const auto& arg : args_) {
        if (arg.kind_ == PathArgument::kindIndex) {
            if (!node->isArray() || !node->isValidIndex(arg.index_))
                return defaultValue;
            node = &((*node)[arg.index_]);
        } else if (arg.kind_ == PathArgument::kindKey) {
            if (!node->isObject())
                return defaultValue;
            node = &((*node)[arg.key_]);
            if (node == &Value::nullSingleton())
                return defaultValue;
        }
    }
    return *node;
}

Value& Path::make(Value& root) const
{
    Value* node = &root;
    for (const auto& arg : args_) {
        if (arg.kind_ == PathArgument::kindIndex) {
            if (!node->isArray()) {
                // Error: node is not an array at position ...
            }
            node = &((*node)[arg.index_]);
        } else if (arg.kind_ == PathArgument::kindKey) {
            if (!node->isObject()) {
                // Error: node is not an object at position...
            }
            node = &((*node)[arg.key_]);
        }
    }
    return *node;
}

} // namespace Json
